This disclosure relates to positive displacement pumps. In particular, this disclosure relates to improvements for rotary positive displacement pumps such as circumferential piston pumps, for food processing or industrial applications.
Pumps, such as rotary positive displacement pumps, can be used to transport fluids through a system. In a rotary positive displacement pump, two or more counter-rotating lobes are disposed in a cavity typically defined by a pump body and an associated cover. This cavity has an inlet on one side of the rotary lobes through which the fluid material is initially received and an outlet on the other side of the rotary lobes through which the fluid material is forced out of the pump. A gear case, which typically supports the pump body, has shafts that attach to the rotors. When the gear case drives the rotation of these shafts, the attached rotors rotate, thereby causing the pumping action.
Although positive displacement pumps of the type described above have existed for some period of time, the continued maintenance and service of these pumps has presented unique challenges. Particularly as health and sanitation standards have become more stringent, maintaining the required levels of cleanliness has become an expensive endeavor, often requiring complex disassembly and reassembly of the pump.
With thousands of pumps of this kind in service throughout the world, there is a continued need for improvements.